export {}

let str1 = 'gggg'
str1 = 'sdsd'

const str2 = 'dfgfdg'
// str2='sef'

//字符串字面量类型
let str3: 'ddd' = 'ddd'
str3 = 'ddd'

// 数值字面量类型
let age: 18 = 18

// 对象字面量类型
let obj: { name: 'jack' } = { name: 'jack' }
